Governor



April 14, 1925 H. F. SCHMIDT GOVERNOR Filed Nov. 29.. 1922 Sheets-Shet 1 lNvENToR ATTORNEY April 14, 1925. 1;,533166 l H. F. SCHMIDT GovERNoR l Filed Nov. 29, 1922 2 Sheets-Sheet 2 n Je a/ W55 28 5.9 ze Jo 76 as :Q7/ 1ra f7-* Hl l o 7 #6 l .sa #a f2 7271# Jo/ "o 2,7

y /w dfsg/ III" l IUI 'l l 70 i sa 7a 77 17 chmidi'. lNvgNToR v ATToRNEYf- Iiate'anted 14, 1925. i

` UNiTEDf `s-'r-ATES PATENT `loiEiCE.

nENmfr E.l SCHMIDT, HOUSE ELECTRIC sYLvANIA.

To all 'whom 'itv may concern.'

Be it known that I, HENRIQ'F: a citizen of the United States, and

.OE ,PHILADELPHIA PENNSYLVANIA, AssIeNon TowEsTrNG- AND MANUFACTURING COMPANY, A CORPORATION OE' EENN-A I GOVERNOR.

SCHMIDT, a resident of Philadelphia, inthe county of Philadelphia and State off invented a Governors, of which specification. v

Pennsylvania, have new and useful Improvement in the following is a.

My invention relatesfto'pressure-responsive governors, of the-dynamic more particularly to those' pressure type, and it has for its object to provide apparatus of the character designated which shall sitive to load conditions,

which shall ybe eco-v lsimple in construction,

be highly senwhich shall be nomical and adaptable in its special requirements, and which shall be suitable for use with high-.power apparatus.

More particularly, my invention has for its object to provide two s pring means for loading a .pressure responsive element, one

of th e spring means being of the floating type, that is, it is under substantially lconi stant tension for moves to different a given adjustment andv positions corresponding to the positions occupied by the pressure responsive device, the

other spring means havingk one endfixedso thatuit constitutes a scalefspring or loads` the pressure respon-,

sive element in accordance with its position, 1n other words, in 'a elongation of the latter spring means.

A further object of ccordance with. the

m invention. is to provide means. whereby t e tension of the load spring may be adjusted to adapt the apparatus for governin g at different speeds and while it is in service.

vA still further object of my invention is to provide a fluid ing mechanism and 'the controlled thereby.

Apparatus Aembodying features pressure governor which is suitable for operating ,largeengine' or turbine -valves employing fluid vor between the governf partgope'rated or vention Aisillustrated in the accompanying drawings, forming a part of 'this application, in which Fig. 1 'is a diagrammatic view of mechanismV showing governing apparatus a 2- is a sectional view o sure-responsive governi myimproved plied thereto;l Fig. myimproved presng device; .and Fig.

sure-actuated suremay be imposed Application sied November 29, 1922. serial Na. 604,033. 5

develops pressure in accordance with the Such a' system has em-` the dynamic type vwhich square of the speed and a pressure-responl sive device for actuating the energy-controlling means oi' admission valve. Ordinarily with large turbines, a relay lis employed so that Aforces other than those developed byv the governor serve to move the heavy valve parts and actuatingmechanis My'kinvention relates to apparatus of this giving'sensitive results without the employment of an intermediate relay. The lsimplest form of pressure-responsive device is an abutment or piston subject to Huid pressure i y 5 on ones'ideandto spring pressure on. the other side; however, with high Huid pressures, the spring becomes inordinately4 long and `impractical in order that suflicient presa y'suficient range of movement permitted. Accordingly, it is the object of my invention to provide apparatus which-will give the vrequisite ,spring pressure and permit the ilse yo ifi'elatively short spring means and which will,` at 'thesame time, afford ample range of controlling movement.V More particularly, my sure-responsive valve connected to an operating piston by' a. strong-Or load spring which Vis normally under tension to resist the major portion of the fluid pressure,the

valve being connected to a stationary element by ai weaker springwhich. assists the i. strong spring in opposing the'luid pressure. Changes 'in Huid-pressure are taken care of by adjustment of lthe operating piston and of the piston valve sucli thatthe` 'weaker spring is elongated more or less to, compensate' for .sion of the strong spring being substantially pressurev changes, the tenlcharacter and 'more particularly, to a pres- 1 sure-responsive device-which iscapable of and, at the same time, I

.inventioncomprises a presconstant for diiferentyregulated speed' positions for a given speed. The speed may be changed by adjusting the tension of the strong or load spring.

InFg. 1, I show a rotary mechanism, at 10, forexample, an elastic-fluid'turbine, which is provided with controllable energy supply means 11, for example, an admission valve, whose position is determined by a motor device, at 12, which acts in response to the pressure of fluid developed by a pump `receptacle 19, and the latter is connected to the inlet of thevpump, so as to constitute in effect a closed fluid circulating system. The pump, or equivalent means, should be of the dynamic ,or pressure type, as it should de-l velop a fluid pressure which varies approximately as the square of the speed of the rotary element 14; and, as the fluid pressure ,speed of the rotary varies, the motor device, at 12, acts upon the energy-controlling means 11 to govern the mechanism.

The structure of the motor device will be clear yfrom a consideration of Figs. 2 and 3. Oil under pressure is suppliedto the motor device 12 and it passes up through the hollow piston valve 21, which is closed at its upper end by any suitable means, for example, by a cap piston valve in a manner to be described. The hollow piston valve 21 has a close fit with respect to the .interior surface of a hollow operating piston structure 24, which is provided with an intermediate operating piston `portion 25 and with upper and lower Fhollow piston-rod lportions 2 6 and .'27, the latter portions having a close {it with the flanges 28 and 29, respectively, constituting cylinder heads for the cylinder 30 within which is located the operating piston portion 25. The upper-hollow piston-rod por- I and 38; and, in order thatA an accurate re".

. 36 are-arranged re tion 26 is connected by any suitable means, for example, the link 32 and the .lever 33, to the rod 34 of the admission valve 11.

, The piston valve 21'is provided with upper' and lower ports .35 and-36, which are adapted -to communicate' with' the ,portsg'37 and 38, respectively, in the vpiston portion 25, the latter ports leading, respectively, to

piston portion 25.' The provided with piston valve 21 is cut-off position, as indicatedin Fig. `.2, cover the ports 37 and 38, respectively, substantially without any lap.

-As. shown'in Fig. 2, the portsr35 and4 ectively above and-be f low the upper and lowerv piston ports-137 'lation may-.be secured between the. piston valve and the piston ports, the ports 35and 22, for action upon they '.57 of the floating the spring to the piston valve.

`upper and lower'. portions: 41 and 42., which, whenthe parts arein a,"

`tion 27, An

'connection 67 with respect 36 terminate exteriorly in enlarged recesses or ooves 43 and 44, which define the outer limits of fthe cutoff-portionsy 41 and/42, respectively, and 38 with no lapV when the piston valve 21 and the operating piston 25 are in a neutral or cut-off position; e

Between the cut-olf portions 41 and 42, the piston valve 2l is provided with Aa portion 46 of lesser, diameter than the hollow interior vof the operating piston so` as to dene the inner limits of said cut-off portions 41 and 42 and to afford communication between the ports V37 or 38 and the ports 47 of the operating piston portion 25 leading to the exhaust space 48, which coinmunicates with the exhaust outlet 49 con-` nected by a conduit 50 to the exhaust line .to the exhaust line 18. f f

V, The upper portion of the piston -valve is 'preferably of a reduced diameter, as at 51, so as to allow the fluid which leaks by to readily flow out through the off-take ports 52 in the piston portion 26, the olf-take chamber 53, theofl`take port 54, and/the conduit 55 to the exhaust line 18.

The piston valve 21 is connected to the which fit over the recesses 37 y lower end of the operating piston rod poition 27 by means of a strong or load spring type, the piston valve 'spect to the operating piston 25. rlhis spring ispreferably connected to the upper end of the piston valve 21 by means of a bolt 58 which is accessible by removal of the cap 22, and the bolt is provided with a nut 59 fitting within the upper convolutions Aof the spring 57 to securely connectl The lower end of the spring 57 is connected to the lowerhollow operating piston portion .27. by means of an adjustable connection sowhich serves to bias 21 downwardly with rei-io that the tension of the spring may be -adjust'ed `in the manner and for purposes hereinafter set forth. y

The tension-adjusting and securing means for thelower end of the spring 57 comprises a threaded -member'62, securely fitted within the lowerconvolutions thereof, and the threaded member is connected ,to an exteriorly 'threaded sleeve 63 having' a-spline connection, at 64, with respect to a collarV the operating piston rod por-v interi'orly threaded sleeve 66 engages with the exteriorly threaded sleeve- 63and it has, atits upper vend, a swivel to the lower end Y of the operating pist-on rod portion 27 The spider 71 secured to the lower end of said ring worm gear 68"maintained in t hand wheel 74 in -ateriorly threaded sleeve 66 has a spline connection, at 68, with respect` to an operatposition by means of a shoulder 69 on the cylinder structure 19' and by a shoulder 70 on the cylinder structure. The worm gear 68 isv rotated either in one direction or `the other by .means of a worm 72 secured to a shaft 73, which is provided with an operating hand wheel 74.

The tension of the spring 57 may, therefore, be varie merely by operating the The operation of the hand wheel results in lrotation of the worm gear 68', lrotation of the interiorly threaded sleeve 66, due to the spline connection at 68, and relative'longi-l tudinal movement between the exteriorly threaded sleeve 63 and the interiorly thread- 'ed sleeve 66, due to the fact that the former sleeve does not rotate because of having the spline connection 64 with respect to the ring 65 secured to the hollow operating portlon 27. The swivel connection 67 of the interiorly threaded sleeve 66 with respect to the lower hollow operating piston portion 27 permits of said sleeve being carried 4by the operating` piston to its different positions and the splined connection'68 of the sleeve with the gear 68', permits of-relative Ymovement of the sleeve with respect to the gear so that the sleeve may berotated for different operative positions of the operating'piston. C

The upper end of the hollow piston valve 21 is also connected to a suitable stationary 'element 75, carried by the spider 71, by means of a spring 76 which serves to bias the piston valve downwardly with respectto the stationary element 75. The spring 76 is` relatively weaker than the spring 57 and constitutes the scale or governing spring of my apparat-us.

In operation, the dynamic pump 13 develops pressure of fluid which varies as a function of the speed of the rotating element 14. The fluid under pressure enters the operating cylinder structure 19 by means of the conduit 17 and it passes through the `spider and up through the piston valve and operating piston structure to act upon the4 The pressure of fluid acting upon the pis-l ton valve 21 is opposed both by the tension of the load spring 57 and by the tension'pf the governing or scale spring 76. Under normal operating conditions, the major portionl of the one direction or the other.

fluid pressure is resisted by the'V tensionof the'spring 57, the sprin 76 serv- I ing toofer a variable resistance ependingl upon the position ofthe piston valve 21 and the operating piston 25 as the speed changes and the pressure'of fluid varies. Y

Assuming that the parts are in Athe position as shown in Fig. 2, with the spring 57 under tension and offering the major portion of the reaction which opposes the pressure of Huid, the reaction offered by the spring 76 being dependent upon the position of the (piston valve 21, then upon an increase in flui pressure, due to an increase in speed A of the rotating element, for example, upon av decrease in load thereof, the hollow piston valve 21 immediately moves upwardly; and, just as soon as this upward movement commences, the ports 36 afford communication with the ports 38 to supply fluid under pressure to the lower face 40 of ythe operating piston25 so as to cause thelatter to movevv upwardly with and relatively to the hollow plston valve 21, and the space above the face 39 is placed in communication with the exhaust by way of passages 37, reduced portion 46, ports 47, and the reduced portion 48. xL The initial movement of the hollow piston valve 21 results in t-he springsj57 and 76 being elongated to the same extent; but, as the spring 57 is much stronger, it will `bear the greater portion of the increase in load. As soon as the operating piston 25 beginsto move, due to the supplyfoffuid under'pressure to the lower face 40 and to the exhaust of fluid from the upper Vface 39, 10

as thelower end of the spring is secured to, 110.

a stationary element.

As the operating piston 25, therefore, follows the fpiston valve 21, such parts move until the increase in pressure of the fluid is compensated for by elongation erning or scale spring 76; and, when this condition is reached,l the operating piston 25 and the hollow piston valve 21, move rela-v tively so that the parts are' in the position indicated in Fig. 2, with theports 37 and 38 '12,0 cut-off by the portions 41 and-42, respectiver ly, of the hollow piston valve.

A. decrease in pressure in the fluid delivered to the operating cylinder structure, resulting lfrom a decreased speed of vthe ro- S125 tary mechanism and, therefore, to an overload, results in downward movement of the l hollow piston valve 21 so asto afford communication between the ports 35 and 37 to supply oil'under' pressure tothe piston face ,130

influence of fluid pressure 105,

Jof the govunderstood from the following example.

39 and communication of the ports 38 with the exhaust ports 47 by means of the reduced lportion 46. The 'piston valve 21 moves downwardly due to the pressure exerted by the springs being superior tothe oil pressure. The piston valve 21 and the operating piston 25 then move downwardly and relatively to each other until the large or fioating spring 57 is again substantially under its normal tension and the spring 76 has been sufficiently shortened or reduced in tension to take care of the decrease in fluid pressure.

It. will, therefore` be seen that the large scale oating spring 57 exerts substantially a constant resistance to the fluid under pressure, this substantially constant tension being maintained due, to the fact that the operating piston is capable of following and moving relatively to the hollow piston valve 21; and, as the piston valve 21 and the operating piston 25 are capable of occupying varying elevations, the spring 76v will be elon ated in a variable manner to take care uctuatlons 1n fluid pressure brought about by load variations on the machine.

With the large fioating spring 57 under tension, it will be seen that such tension is resisted by the body of fluid in the operating` cylinder particularly above the piston face 39. Therefore,- with the parts in a neutral or cut-off position as shown in Fig.V 2,

it is necessary that the portion 41 shall have such a dimension -with respect to the port 37 as to permit a slight leakagge' of fluid under pressure in order to make up for such 'leakage as takes place above the operating pistonface 39. 1

The governing mechanism may be adjusted to maintain different speeds merely by varying the tension of the large scale spring 57 which may be readily donefwhile the machine is inoperation merely by turning the hand Wheel 74. Operation Iof the hand wheel results either in increased Yor diminished tension of Vthe large scale spring 57 so as to vary the value of the load pressure to be maintained. As the'piston valve .21 comes toa neutral or cut-olf position when the vspring and fluid pressures are in equilibrium, it will be obvious that upon variation in the tension of the load spring 57 a correspond- -ing variation of the vfluid pressure is rejquired to bring` about an equilibrium condition, and, as the Huid pressure required varies, of course, the speed of the; governed mechanism varies. f

The' operation of theApressure-operated governing mechanism will be more clearly Assume that the total ilpressure acting on the piston valve 21 1s 928 pounds, that 776 `'pounds is opposed by tension of Vspring 57 and that152 pounds is opposed rif y the A"tension ofthe governing or scale rvarying loads.

the load times as much load as the spring 76, in other words, for a pressure increase of 32 pounds the large spring may be increased to an extent of 28 pounds and the small spring'to an extent of 4 pounds. As soon as the operating piston is capable of moving, it will move until the tension upon the large spring is relieved to the extent of this increase, and when this takes place the piston valve and the operating piston are in a neutral cut-off position but they occupy such a position as to cause such elongation of the .small spring 7 6 as to take care of the additional pressure of 32 pounds. It will, therefore, be seen that the small spring 76 acts as a scale for varying pressures and that the large spring 57 acts to impose an approximately constant load, for a given setting, for all positions.

Downward movement of the operating piston structure, in response to a decrease in fluid pressure, results in downward movement of the link 32 and upward movement of the rod 34 to open the admission valve 11 ywidenso as to supply more motive iuid to 'the motor, at 10, in order to take care of the ,flow of motive fluid to the motor, at 10. If

the spring 57 is adjusted so as to respond to low fluid pressures, it is obvious that the motor, at 10, may be governed by the apparatus to operate at a low range of speed.

As the `tension of the spring 57 1s increased,

the motor speed is also increased to the extent of developing fluid under pressure which will `counterhalance the tension of the springs.

From the foregoing, it will be apparent that I have devised a simple and sensitive speed-responsive, fluid-operated governor in which fluid pressure is opposed by spring means which may be made reasonably short with the capability of resisting high pressures and with the preservation of adequate governor movement to secure a fine ad]ust ment of the admission valve'to take care of It will also beobvious that operating forces of sufficient magnitude and duration are involved to obtain the requisite movement Vof the admission valve without the employment of 'the usual relay mechanism for this purpose.`

While I have shown my invention in but one forni, it will be obvious to those skilled in the art that itis notl so. limited, but is susce tible of various other changes and modi cations, without departing from -the spirit thereof, and I desire, therefore, that `only such limitations shall be placed' thereupon as are imposed by the prior art or as ,are specifically set forth in the appended claims. e f

What I claim is: i 1. In a fluid-pressure operated mechanism, the combination of a fluidpressure operated element, acontrolling element for the operated element and movable in response' to a var1at1on 1n fluid pressure, ,blas- .ing means movable with the controlling element and opposing the fluid pressure imy osed on the controlling element, and other iasing means effective in the same direction as the first biasing means and connected to the 'controlling element and to a stationary element.

2. In a pressure-responsive governor, the

. combination of an element Amovable in response -to fluid pressure, means for controlling the admission and exhaust vof fluid under pressure to said element and subJect thereto,

posing the force of fluid and other Ameans'for imposing a. force on the controllingmeans in oppos1tion 'to fluid pressure in one direction, means movable with theV controlling means foroptothe fluid pressure forcewhich 'varies in accordance with the position of thecontrpllingmeans. I f A 3. The combination-with .a motor` having an admission valve, ofgoverning mechanism for controlling -the position of theadmissionv valve comprlsmg means for developing pressure of fluid ydriven'by the motor, means actuated" by the fluid `under pressure for moving the admission valve, controlling vmeans .for admitting andexhausting fluid to` the actuated means and. movable in one direction by the fluid under'pressure, biasing means movable with'the controlling means for exerting pressure thereon in the other direction, and means for exerting pressure o n the controlling means in said other direc- 59 tion in accordance with position of said controllingl means.

4. In a fluid-pressure operated 'mecha-l l. ynism, the combination of an operated ele ment, a controlling element for tle oper-I ated element and vmovable in response to a variationfm fluid pressureha floating sprmg for connecting theelementsA and whosetension opposes the fluid pressure, fand a spring 'for connecting the controlling element to a stationary element pressure.v l

5. In a pressure-responsive governor for and opposing the fluid .controlling rotating machinery, the combination of an operating piston, moved 'by fluid under pressure, a valve -for the Ipiston pressure appliedv posing the fluid pressure which is movable in one directionby fluid under pressure, a .floating load spring for connecting the Vvalve and piston and opposing the fluid-pressure on the valve. and a scale or governingspring connected to the valve, opposing t e fluid pressure applied thereto, and fxedat one end.

6. In a pressure-responsive governor for, controlling y.rotating machinery, the combination of an operating piston, a `valve for the piston, a-floating load spring for connecting the p isgm and valve, means for adjusting the vten ion of the load spring, and a scale or governing spring connectedto the valve at one end and fixed at'the other end.

7. In combination in a fluid-pressure gov.- ernor for a fluid motor having a motive fluid admission valve, an operating piston connected to the admission valve and a piston for controlling the admission of pressure fluid to the operating piston, the operating piston and the piston valve being movable to different positions as determined by the speed of the fluid motor, means for exerting a' substantially constant pressure on lthe pisL t0n valve in opposition tothe fluid pressure for different load positions thereof, and

fluid un er pressure to the operating piston Y upon relative movement of the valve with respect to the piston and the admission ofv fluid under pressure being cut off by a relative movement of the operating piston with respect'to the valve, biasing means arranged between the piston valve and the` operating piston and exertinga substantially constant force on they fluid except when the Vpiston valve moves relatively to the operating piston, and biasingv means arranged between thel piston valveyand a stationary element which v assists the. first bia Ying means in opand which serves substantiaA y to' absorb the change in pressure taking place in the first biasing means when the piston valve moves relatively to the operating piston so that the force of said first biasingmeans-is maintained substantially constant when the. piston valve andthe operating piston are in a neutral or cut-off position. 9. a pressure-actuated governor, the combina-tion of an operating iston, a piston valve foradmitting fluid un er pressure to the operating vpiston upon relative movement of the valve with respect thereto in order to secure movement of the operating piston and the admission of fluid `under .pressure being cutoff by relative movement jected on one side to the fluid under pressure, and biasing means associated with the piston valve for opposing the fluid pressure.

10. In a fluid-pressure governor,I the com'- 'bination of a cylinder, an operating piston nected to the piston valve and normally under tension in opposition to fluid under pressure. admitted to said cylinder, one of .the springs being connected to the operating piston and the other to a Stationary element.`

12. A pressure-responsive mechanism comprising a pressure-responsive element, a pair of springs for loading the element against pressure, a vfollowing element to which one of the springs is connected, and a stationary element to which the other spring is connected, whereby, upon a change in pressure, the first element moves to admit fluid under pressure to the second element to move the latter in the same direction, whereupon both elements mbve until the change in pressureis compensated for by the change in tension of the spring connected to the stationary element.'

13. Ina fluid-pressure'governor for a rotating element, the combination of energycontrolling means for the rotating element, a pressure-responsive valve, a movable abutment connected to said energy-controlling means and which is actuated by fluid under pressure admitted by said valve to follow the mot-ion of said valve, means for loading the valve with respect to the abutment Yto resist fluid under pressure acting on the valve and serving to secure actuation of the valve when the fluid pressure changes, and other means for loading the valve to balance it against the fluid pressure whose capacity for loading 1s varied by movement of the abutment to compensate for the change in loadto be governed having an admission valvev and means for developing pressure of fluid 120 which varies as the speed of the motor, of

ing of thc first loading means upon `initial movement of the valve to maintain the latter loading means at a substantially constant value for different operating positions of the governon 14. The combination with a machine whose speed is to be governed, having energy-controlling means, and means for developing pressure of with a function of the speed of the machine, of a pressure-,actuatedl governor comprising an operating element. connected to said fluid in accordance 'energy-controllinof means, a valve for ad-V mitting fluid under pressure upon relative 'movement of the valve with respect to said operating element, the pressure being cut off by relative movement of the operating element with respect to 'the valve, means carr1ed by the valve and which is subject to thepressure of the fluid, and means Afor lexerting pressure on the valve which balances the`pressure of fluid applied thereto. v

'15. In combination with a fluid motor having an admission valve and a pump for developing fluid under pressure which varies as a function of the s d. of the motor, of. a pressure-actuated evice which is connected to the admission valve and which is operated by fluid'under pressure received from the pump, comprising an operating piston connected to the admission valve, a piston valve for controlling the admission of fluid under pressure to th opery ating piston vand s ubject to the effect of fluid under .pressure 1n one direction, tension means -arranged between the piston valve and the operating piston and exerting its effect on the valve in a direction opposite to ,that of the fluid pressure, and other tensionv means arranged between the piston valve and a stationary element and exerting its efl'ect onthe valve in the same direction 95 as the first tension means.

16. The combination with a machine to be governed having an energy-controlling element and means for developing\pressure of fluid which varies as .a function of the speed of the machine, of operating mechanisinmovable to different positions in response to variations in fluid pressure to govern the energy-controllingmeans including a fluid-pressure-actuated abutment, ya valve for admitting and exhausting fluid to the abutment and subject tothe force of the fluid preure in one direction, means for biasing the valve to a pre-determined extent with respect to the abutment to normally 11o oppose to substantially a predetermined extent the pressure of the fluid applied to the valve, and biasing means between the valve and a stationary element for opposmg to an extent determined by the position thereof. y.

17. The combination with a fluid motor pressure-actuated governing mechanism arranged to recelve fluid under pressure from the pressure-developmg means and to actuate' the admission valve in accordance 125 erating piston and movable to' different po- 1.39

the pressure of fluid applied thereto-115 sitions, means for lsubjecting `the valve to Afluid pressure, .biasing means effective between the operating piston and the valve' for opposing movementv of the'latter in reo'and means for developing pressure of fluid which varies as the speed of the motor, of pressure-actuated governing mechanism arranged to receive fluid under pressure from the pressure-developing'meansfand to ac' tuate the admission valve 4in 'accordance with variations-in fluid pressure comprising an operating piston connectedtotheadmis.- sion valve, a valve for controlling/the. admission of fluid under pressure to the operating piston,'means carried by the; latter valve being subjected on loneside to fluid underzpressure, a load spring connecting the operating piston and its valve vand-normally under tension to oppose the fluid pressure, and a. scale or, governing spring arranged between t-he'valve and av stationary element `to `exert additional pressure vagainst gation.

19. The combination with 'a' fluid motor, to bel governed having an admission valve and means for developing pressureof fluid feo vto obtain'a setting of the pressure-actuated governing mechanism arranged to receive. fluid under pressure from the premura-developing means and to actuate the vadmission valve in accordance with variations influid pressure comprising a piston valve for controlling the admission of fluid under pressure fto an operating piston connected tothe ladmission valve so as to cause the "operating piston to follow the motion fof the piston valve and to move relatively thereto to cut oil' the supply of pressure fluidto the operating piston atter which is dependent upon the pressure of fluid, a spring for connecting theplston valve and the operating, piston and being normall under tension so as to exert a -pressurewhic j opposes the fluid pressure, and a spring-for connecting the piston valve and a stationary element which serves to exert a pressure on the piston -valve to oppose the `fluid` ressure dependent upon the position o the piston valve. Y

20. The combination with a fluid moto; having an admission lvalve and means for position of p `suresupp the fluid pressure-dependent upon 'its' `elon-' developing 'pressure' of fluid in accordanceV with the speed of the motor, of'a motor device connected to the admission valve and operative in response toilchanges of fluid pressure tocontrol thel position of the admissionvalv'e comprising an operating piston having upper and lower faces and ports leading thereto, a piston valve having communication with the pressure fluid and f being provided with upper and lower ports normally out of registryy with the operating piston'ports but adaptedto register respectlvely upon downward or upward movement of the piston valve relatively to the operating piston, a load spring forconnecting thev operating piston'and the? piston valve and being normally undertension to oppose the fluid pressure acting on the' piston valve,

and a governingor scale. spring for con-- necting the piston valve and astationary element and being adapted to exertitension uponthe piston valve which varies with the load.l l

21. The combination with a fluid motor having an admission valve and means for the latteras determined by the developing pressure of fluid in accordance with the speed of the motor, of a motor dcvice connected yto the admission valve and operative in response to changes of fluid pressure to control the positionlof'the admission valve comprising an operating piston having upper and lower `faces and resy ports leading thereto, a plston valve having communication with the pressure fluid and being provided with upper and lower pressure supply ports normally located above and below said upper and 4 lower ports .respectively of the operating which varies as the speed ofthe motor, of.'I

piston but-adapted to register therewith respectively upon downward or upward movej ment'oi the piston valve, a 'spring for connecting the operating piston land the piston valve so as to. exert pressure von the latter opposedfto'the fluid pressure, and a scale or governing spring lto exert additional pressure' on thepiston valve which varies with the position of the latter as determined by theload. f

'22'. `The.jcombina-tion with a fluid `motor 4to be governed havingan admission valve and means for ,developing pressure of fluid which varies als the spec of the motor, of amotor devicewhich is operatedA by fluid under pressure and which serves to actuate the admission valve-comprising a cylinder having a pressure fluid inlet, a hollow operating t piston connected to the admission ing the tension of the spring, and a spring for connecting the piston valve with a stationary element carried by .the cylinder.

23. The combination with a huid motor to Ibe governed having an admission valve' and means for developing pressure offluid which varies with the speed ofthe motor, of a motor device which 1s operated by fluid under pressure and which serves toactuate the admission valve, comprising a cylinder having a pressure inlet vport,a hollow operating pistoniitting in the cylinder and connected to the admlssion valve, a hollow pis-I ton valve telescopically arranged with re-I' spect to the operating piston, ports in the pistonl valve and in the operating piston to registerl upon movement of the piston valve relatively to the piston .to a .predetermined extent and tobe cut olf upon relative movement thereof, a strong scale spring for connecting the pistony valve with the operating.

piston, and a relatively yweaker spring for connecting the piston valve with a station- ,ary element. I Y

24; The combination with an elastic-uid` motor to be governed having an admission .masses valve and means for developing pressure of luidwhich varies as the speed of the motor, of a motor device which is operated by fluid underpressure and which serves to actuate to. normally impose pressure upon th'ev piston4 valve which yis opposed to the pressureimposed thereupon by the fluid under pressure,

means for adjusting the tension of saidlspring, and another spring for connectingv the piston valve to a stationary element so as to impose additional'pressurein accordance with the position of said valve to oppose the fluid pressure imposed thereupon.

In testimony whereof, l have hereunto subscribed my, name this 27th day of No vember, .1922.

HENRY F. SCHMIDT. 

